New research links alcohol consumption to certain forms of cancer

According to a new study published Wednesday in the journal Nature, discussed in a Reuters report, alcohol consumption can cause permanent damage to the DNA of stem cells, raising cancer risk for many individuals. The scientists involved in the study explain that a toxin is produced as the body works to convert alcohol to energy, which is harmful to DNA and “damages the genetic information that constitutes the code of life,” according to one of the study’s co-leaders, Professor Kevin Patel, of Medical Research Council Laboratory of Molecular Biology.

The scientists gave diluted ethanol alcohol to mice, and used chromosome analysis and DNA sequencing to evaluate the damage from the toxin, called acetaldehyde. It showed that the toxin can harm the DNA within blood stem cells, causing permanent changes to the DNA there. Patel said that damaged stem cells can lead to the growth of cancerous cells.

“Some cancers develop due to DNA damage in stem cells. While some damage occurs by chance, our findings suggest that drinking alcohol can increase the risk of this damage,” according to Patel.

In particular, seven types of cancer, including common bowel and breast cancers, saw increased risk with alcohol consumption.

Researchers also examined mechanisms in the body for defending against this damage. Enzymes called aldehyde dehydrogenases (ALDHs) break down the toxin into acetate, which can be used as energy for cells. The study showed that the DNA of mice who were lacking an ALDH enzyme sustained four times as much damage as mice with a properly functioning version of the enzyme.

A backup defense system, according to Patel, involves DNA repair mechanisms that, in most cases, are able to repair damage from many different causes, including alcohol consumption. But in some cases, and for certain individuals, these mechanisms do not manage to repair the damage properly, leading to permanent harm. According to genetic data, these issues repairing damage are particularly prevalent in groups of people from Southeast Asia.

According to Patel:

“It’s important to remember that alcohol clearance and DNA repair systems are not perfect, and alcohol can still cause cancer in different ways – even in people whose defense mechanisms are intact.”

The study was funded by Cancer Research UK. The International Agency for Research on Cancer (IARC), a branch of the World Health Organization, already classifies alcohol as a Group 1 carcinogen, due to “convincing evidence” that it can lead to cancer.

One prior study, in 2011, found that 4 percent of all the cancer cases in Britain can be linked to alcohol consumption.